Diaphragm valve with projections around bleed hole



United States Patent Inventor Myles N. Murray Chagrin Falls, Ohio Appl. No. 774,119

Filed Nov. 7, 1968 Patented Dec. 1, 1970 Assignee Industrial Electronic Rubber Company Twinsburg, Ohio a corporation of Ohio DIAPHRAGM VALVE WITH PROJECTIONS AROUND BLEED HOLE 6 Claims, 4 Drawing Figs.

U.S. Cl 251/38, 251/30, 251/45 Int. Cl ..F16k 31/385 Fl6k 31/40 Field of Search r. 251/46, 45,

References Cited UNITED STATES PATENTS 2,939,927 6/1960 Rozel et a1. 25l/45X 2,993,676 7/1961 Dahl 251/45X 3,245,651 4/1966 Erickson 251/129 Primary Examiner-Arnold Rosenthal Att0rney-Oberlin, Maky, Donnelly & Renner ABSTRACT: The flexible diaphragm has an annular fold the inner wall of which is rolled in the opening and closing action of the diaphragm, and the inlet bleed hole through the same is located near the outer edge where comparatively little flexing occurs to minimize crack growth. The exterior of the fold is provided with bumps to preclude blockage of the bleed hole and assist in dislodging scale and the like in flexure of the diaphragm.

1 DIAPHRAGM VALVE WITH PROJECTIONSAROUND' BLEED HOLE This invention relates to an improved form of pressure operated diaphragm valve.

More particularly, the basic valve form with which the invention is concerned comprises concentric inlet and outlet chambers at the same side of the diaphragm, with a first relatively small fluid communication path from the inlet to the opposite side of the diaphragm and a second relatively large path from the latter to the outlet. The second communication path is normally blocked, and fluid is conveyed from the inlet through the first path to and contained at the opposite' side of the diaphragm to maintain the same against the outlet in valve closing condition. The valve is opened by unblocking the second path for discharge of the fluid from the opposite side to the outlet at a rate greater than inflow through the first path, with the resulting drop in pressure across the diaphragm causing the same to be moved away from th'e'outlet.

The first communicating path has been most conveniently provided by a bleed hole in the diaphragm and the second by a central passage in the same, with the inlet thus of course about the outlet. The designmust insure that the bleed hole is not blocked inthe displacementor distortion of the diaphragm and it has been the practice accordingly to locate it close to the center, and usually thickened, part of the diaphragm.

With this class of valve, as used for example in controlling water supply for an appliance such as a clothes washing machine, it has been common to form the elastic diaphragm with an outward fold or hump between its center outlet valving section and its outer edge, so that this portion unrolls for the opening movement. Most of the flexure in the rolling action occurs at the inner side of the fold and this is where the bleed hole has been conventionally placed for the reason noted above. However, the 'hole at such location constitutes an incision which accelerates theflex crack growth rate of the diaphragm and thereby causes failure earlier than need be the 7 case.

It is a primary object of the present invention to provide such a diaphragm valve in which the noted adverse effect of the bleed hole is substantially reduced, while maintaining the essential protection against obstruction of the same in the operation ofthe device.

Another object is to provide such an improved valve in which the diaphragm hasan added degree of self-cleaning ac tion with respect to water scale and other deposits which may tend to form on the same. v

Other object and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and relatedends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

In said annexed drawing: 7

FIG. 1 is a vertical section of a diaphragm valve inaccordance with the present invention; i

FIG. 2 is an enlargement of a portion of FIG. 1 in which the valve is shown in closed condition;

FIG. 3 is a comparable enlargement with the valve in the open condition; and

FIG. 4 is a fragmented section indicated by the line 4-4 in FIG. 2.

Referring now to the drawing in detail, the illustrated valve comprises a body or housing of one-piece molded plastic form with an annular inlet 11 in spaced concentricity about a cylindrical outlet 12. The inlet extends to an integral threaded fitting 13 for connection ofa supply line, such as the water line to a domestic clothes washer, while the outlet continues to a nipple 14 having a delivery hose 15 stretched over the same.

The topof the body about the inlet is formed with an annular groove 16 and the section 17 between the same and the inlet is slightly relieved. The body section between the inlet and the outlet is a cylindrical wall 18, and its upper end will be seen to be slightly depressed relative to the body end section A flexible diaphragm designated generally by reference numeral 19 is arranged against and extending over the inlet and outlet. This diaphragm, preferably made of rubber or a plastic of good flex life, such as polypropylene, is molded to the shape shown in FIGS. 1 and 2 and thus has an outer peripheral flange 20, an intermediate folded section 21, and a thickened central portion 22. The outer flange is received in the body groove 16 and the center portion seats against the top of the wall 18 to close the outlet 12, with the fold thus over and extending upwardly from the inlet 11.

A bell form cap 23 of nonmagnetic metal is placed on the diaphragm, with a bottom flange 24 overlying the outer diaphragm edge, and thediaphragm and cap are clamped to the body 10 by an overlapping retainer ring 25 fastened to the latter by screws 26. The lower portion of the cap forms cooperably with the diaphragm a chamber 27 at the opposite side of the diaphragm from the inlet and outlet and communication respectively therebetween is providedwith a small bleed hole 28 in the outer wall 29 of the diaphragm fold and an axial passage 30. The hollow stem part 31 of the cap is alined with the en central diaphragm passage and contains a magnetic armature 32 and a light bias spring 33 above the same. The lower end 34 of the armature is pointed, and the diaphragm passage 30 is shaped to have an outwardly diverging upper end portion 35and an intermediate cylindrical seat 36 against which the pointed end of the armature bears to close the same in the normal vertical orientation of the valve.

A lifting solenoid 37 is mounted on the stem 31 and, when energized, draws the armature upwardly to open the diaphragm passage 30.

The valve is normally closed as shown in FIGS. 1 and 2 and, with connection of the inlet to a fluid supply, such as a household water line, the water will, through the bleed hole 28, fill the cap chamber 27 and thereby maintain the diaphragm in the outlet closing condition. When it is desired to open the valve, the solenoid 37 is energized and the armature 32 lifted to unblock the central diaphragm passage 30, theminimum diameter seat part 36 of which will be seen to be of substantially larger area than the bleed hole 28. There will consequently be a discharge of the liquid within the cap to the outlet at a rate much greater than inflow of the liquid through the bleed hole and consequently, there is a pressure dif' ferential across the diaphragm moving it upwardly or away from the outlet. i

As will be evident from a comparison of FIGS. 2 and 3, the

I openingmovement of the diaphragm causes unrolling of the diate fold or hump section at the inner wall of the same; When the solenoid is deenergized, the armature drops to close the central diaphragm passage and the resulting increase influid pressure in the cap causes the diaphragm to return to the closed condition with a reversal of the unrolling action.

The inner wall of the diaphragm fold is thus the part which is flexed the most, and the lower portion of the outer wall 29 of the fold where the bleed hole 28 is located by comparison experiences relatively small distortion. The effect of the hole on the flex crack growth rate of the diaphragm is therefore relatively reduced in this configuration for extension of the useful life of the diaphragm.

It is of course important that the bleed hole remain unobstructed in the flexing of the diaphragm, since closure of the same, for example, by this section being pressed against the surrounding wall of cap, would render the valve inoperative, and the fold section is provided with external projections to avoid such blockage. These projections are small spaced and pointed protuberances 38 extending over the area from below the bleed upwardly over the fold or hump and fully about the same. For the purpose of assuring communication externally to the bleed hole, it is necessary only to have such protuberances in the immediate area of the hole, but the preferred distribution of the same substantially over the entire fold section enhances self-cleaning of the diaphragm, with these irregularities assisting in dislodging scale and dirt as the diaphragm flexes.

lclaim:

1. A diaphragm valve comprising a body having an outlet and an annular inlet in spaced concentricity about the outlet, a flexible diaphragm extending over the inlet and outlet with its central part normally against the latter, means for clamping the peripheral part of the diaphragm outwardly of the inlet to the body and forming a chamber at the side thereof opposite the inlet and outlet, the diaphragm at an intermediate part over the inlet having a normal outward fold which unrolls at its inner side and returns for movement ofthe central part toward and away from the outlet, a bleed hole being provided in the diaphragm at a point in the outer side of the fold which experiences comparatively little flexure in such movement as compared to such inner side, said hole establishing supply fluid communication between the inlet and said chamber, the diaphragm being further provided with a plurality of exterior protuberances extending into said chamber at least in the area around the hole, said protuberances comprising means to space said hole from said clamping means to preclude blocking of the hole in all positions of the diaphragm, and means for dumping fluid from the chamber at a rate faster than that of inflow through the bleed hole to pressure actuate the diaphragm away from the inlet and outlet,

2. A valve as set forth in claim 1, wherein the protuberances are small projections in spaced distribution substantially fully over the exterior of the outer side and top of the fold in the relatively unrolled pressure operated condition of the diaphragm.

3. A valve diaphragm comprising a relatively heavy center section formed with a central axial passage, an annular folded section formed integrally with and extending around such center section, said folded section including a radially outer wall portion and an inner, flexible wall portion which rolls and unrolls in response to as axial movement of said center section. said outer wall portion terminating in an outer peripheral clamping section including an annular, laterally extending mounting flange, said outer wall portion being formed with a bleed hole in the lower region thereof adjacent said mounting flange, the exterior of said outer wall portion at least in the area around said bleed hole having protuberances which space the hole inwardly from the outer most surface of said area thereby to preclude blockage of said bleed hole, said axial passage in said center section being of appreciably larger area than said bleed hole.

4. The diaphragm of claim 3 made of molded plastic having a flex life on the order of that of polypropylene.

5. The diaphragm of claim 3 made ofmolded rubber.

6. A diaphragm as set forth in claim 3, wherein the protuberances are sa small projections in spaced distribution substantially fully over the outer surface and top of the folded section. 

